The placebo effect is a powerful concept that has been proven over and over again in many different studies. For those who don’t know, it is a concept where if someone thinks something is going to work, it is more likely to work, regardless of whether it actually should work or not. This is most commonly used in medical situations.

For example, if you have a headache and are given a pill that you are told will provide you with pain relief, your headache will likely go away even if the pill you were given actually has no medicine in it.

This concept can be used in many different scenarios, and there is even evidence that it works if the patient in question knows that they are being given a placebo, which makes it even more impressive.

The opposite of a placebo, called a nocebo, is also real. If someone goes into a treatment thinking that it is going to cause them pain (or another unwanted effect), it is more likely to result in real pain in the patient. There are quite a few studies showing this as well.

What hasn’t been properly studied, however, is how placebos and nocebos work when directly compared to each other, so that is what a team set to do. Their study, which was published in the journal eLife, found that while placebos certainly work, nocebos work even better and have longer lasting effects.

This unfortunate result will hopefully be a reminder to all medical professionals that while it is critical to provide patients with accurate information about their condition, it is also important to avoid making them think that their results will be worse than is actually expected.

The team working on this study had 104 healthy people come in for two separate sessions, which were conducted one week apart. In a statement, study co-lead author Katharina Schmidt talked about what happened next:

“We used a sham electrical device that participants expected to work with three different stimulation frequencies: a neutral one; a frequency that alleviates pain; and a frequency that augments pain.”

In reality, the device did not do anything to cause or alleviate pain. Instead, it simply caused a heating sensation that got warm enough to be uncomfortable but not cause actual burns. For the first visit, when the patient was told the pain would go lesson, they turned the heat down. When they were told it would increase, they turned the heat up. On the second visit, they left the heat at the exact same level regardless of what the patient was told.

The results showed that when patients were told that pain would get worse, it did. When the heat actually turned up, they rated their pain 11.3 points higher than the control group, and when the heat did not change at all, they still rated the pain 8.9 points higher than control.

On the placebo side, the results were also notable, though less extreme. When patients were told that the pain would lessen and the  heat was turned down, they reported pain at 4.2 points lower than the control group, and when the heat did not change, they reported 4.6 points lower.

Senior author of the study, Dr. Ulrike Bingel, talked with IFLScience about the results, saying:

“Negative expectations, fears and anxiety are ubiquitous in clinical care. Previous experimental and clinical work has shown that nocebo effects resulting from these can impair the efficacy of drugs and other medical treatments and increase side effects. It is very important to be aware that nocebo effects are triggered even more easily than placebo effect and, unfortunately, tend to persist longer once triggered. This is a very important finding. Physicians and other [healthcare professionals] should be aware of this effect and the key role of their communication with patients in mitigating and avoiding these effects.”

This data can be used by doctors and other medical professionals to help determine exactly how they should communicate with patients to give them the information they need, without causing unnecessary pain, suffering, or other negative results.

It is remarkable just how much of an impact the placebo and nocebo effect can have.

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